Rudder Failures

[neilpride]

Nothing personal, but all this IRC numbers or whatever ,,make me dizzy, most modern cruising boats have a médium sailing speed range around 6 knts , thats enough for me, if you can squeeze more to gain that 9 or 10 knts good to, Smack Hunter have a hull speed around 7,5 knts and i dont understand all the argue about the rating, so far so good is able to make 5 or 6 regular, do you call that fast?

Some modern hulls are able to surf at 10knts, others at 9 , you see , the diferences are minimal, Dockhead made a good point, in the rough upwind the heavy cruiser won, and even in moderate winds my 2 cents, since most moder production boats are trimmed in their hulls for beam reaching and DWD sailing, the prevailing wind conditions.... im amazed about the last edition of the Route du Rhum , Loick Peyron and the megabeast trimaran in 7 days, wow, thats from the north tip of france to guadaloupe, thats not sailing , its flying, soon the french sailors are going to develop a new category , waterflying!! im sure Loick or others wana made it in less than 5 days...

So far so good if i have a cruising boat with a decent speed to make between 150 or 200 miles per day im happy , 6 ot 7 knts are good and enough for cruising, the rest is pushing the design to limits, or like Dockhead say it very well, pay waterline,,, Sundeer its a good example,
Two same identical hulls, rigs, keel, rudders, materials used, one sailing at 6 the other at 10, i take the slower one any day because the faster one i know for sure is build it ultralight....
Cheers

[noelex 77]

Originally Posted by Polux

An Open 60 weights about 8000kg, that's about weight of my 41ft sailing boat but I am pretty sure than an Open 60 is more seaworthy than your boat. Basically this has to do how the stability is obtained. Regarding overall stability your boat and an Open 60 should not be far but while your obtain the stability with a small arm (GZ) and a big weight, the Open 60 obtains it by a small weigh and a huge arm. That gives about the same static stability to both but a hugely better dynamic stability to the the Open 60.

The stability curve is only a tiny part of what makes a boat seaworthy. Some of the features that enhance the stability curve will actually detract from the overall seaworthiness of a yacht.

To judge the relative seaworthiness of two yachts, especially two such disparate models as an Open 60 and Moody 54 by comparing only their stability curves is not going to be very productive.

[Polux]

Originally Posted by neilpride

Nothing personal, but all this IRC numbers or whatever ,,make me dizzy, most modern cruising boats have a médium sailing speed range around 6 knts , thats enough for me, if you can squeeze more to gain that 9 or 10 knts good to, Smack Hunter have a hull speed around 7,5 knts and i dont understand all the argue about the rating, so far so good is able to make 5 or 6 regular, do you call that fast?

Some modern hulls are able to surf at 10knts, others at 9 , you see , the diferences are minimal, Dockhead made a good point, in the rough upwind the heavy cruiser won, and even in moderate winds my 2 cents, since most moder production boats are trimmed in their hulls for beam reaching and DWD sailing, the prevailing wind conditions.... im amazed about the last edition of the Route du Rhum , Loick Peyron and the megabeast trimaran in 7 days, wow, thats from the north tip of france to guadaloupe, thats not sailing , its flying, soon the french sailors are going to develop a new category , waterflying!! im sure Loick or others wana made it in less than 5 days...

So far so good if i have a cruising boat with a decent speed to make between 150 or 200 miles per day im happy , 6 ot 7 knts are good and enough for cruising, the rest is pushing the design to limits, or like Dockhead say it very well, pay waterline,,, Sundeer its a good example,
Two same identical hulls, rigs, keel, rudders, materials used, one sailing at 6 the other at 10, i take the slower one any day because the faster one i know for sure is build it ultralight....
Cheers

You talk like a cruiser to whom sailing pleasure is indifferent but not all are like that. For some the pleasure of sailing is as important as sailing.

The difference you talk about speed is much more important. With the same size (40/42ft) a heavy boat average medium speeds of about 5.5K, performance ones about 7K. It looks not much but in 24 hours regarding the slower boat that means more 6.5 hours and a 15 days passage for the faster boat it will mean more 4 days. That's about the difference you see on the ARC regarding the average time passage between the two types of boats.

Comet 41s Alma, 2013. - YouTube

But more important than that are two other things: the pleasure of sailing a fast enjoyable boat, not to mention the pleasure of overtaking much bigger boats and, out of the trade winds, the incomparably more time one passes sailing than motoring.

To give you an idea last year I made about a 1000 NM cruising with 60L of diesel, most of it for charging the batteries, since i did not use the engine practically for nothing more. With a medium displacement boat I would be motoring 2/3 of the time and would have spent about 10 times more diesel.

But is not really a question of wasting money in diesel, it is about the pleasure of sailing instead of motoring. I like to sail as much as I like to cruise

[Dockhead]

Originally Posted by noelex 77

The stability curve is only a tiny part of what makes a boat seaworthy. Some of the features that enhance the stability curve will actually detract from the overall seaworthiness of a yacht.

To judge the relative seaworthiness of two yachts, especially two such disparate models as an Open 60 and Moody 54 by comparing only their stability curves is not going to be very productive.

You beat me to it. Stability does not equal seaworthiness! Stability is in fact a quite small part of the picture of seaworthiness.

Much bigger parts of that picture are size and mass. Mass works against speed. That is why if you want a fast, seaworthy vessel, it has to be bigger.

That actually brings us back to production boats - if you can buy a 45' Bene for what you would have paid for a 32' Contessa, intimidate in today's euros - you've picked up a ton of speed. But size has made up for the loss of seaworthiness from lower D/L. That's one reason why boats have gotten bigger recently. That is a very worthwhile tradeoff.

[Polux]

Originally Posted by noelex 77

The stability curve is only a tiny part of what makes a boat seaworthy. Some of the features that enhance the stability curve will actually detract from the overall seaworthiness of a yacht.

To judge the relative seaworthiness of two yachts, especially two such disparate models as an Open 60 and Moody 54 by comparing only their stability curves is not going to be very productive.

That was what I was talking about. I was talking about dynamic stability and not about the RM curve:"when your boat is knocked down is making the same RM to get up on its feet as a Open 60 but the difference is that the same force is trying to right a boat with 20 T while regarding the Open 60 the same force is trying to right 8 T. In fact even with the same RM, considering weight, the force on the lighter boat is 2.5 times more efficient."

This is not about the RM stability curve but about dynamic stability.

[Dockhead]

Originally Posted by Polux

Things are still a bit confusing about relative boat performance. I have already said that the Moody 54 was a relatively fast boat regarding that vintage and in fact I like the boat design, specially the hull ( not the keel or the ruder) even if we have to put things in perspective regarding when the boat was designed (and that was the norm then for that type of boats). The hull is advanced for its time in my opinion.

But when things get messy is with the comparison of the performance of older middle displacement boats with main market modern boats and even worse in what regards with performance cruisers. Bigger boats are faster then smaller boats if they belong to the same type, not necessarily if we talk about different types of boats.

Somebody had said with all justice that ratings regards boats with a minimum sailing load and not boats loading for cruising and that a big boat will be less affected then a small one, in what regards the loss, regarding the rating performance. Even if all don't voyage with the same load and the ones that have performance boats tend to be more spartan, that is obviously true. So some discount has to be given regarding that, but I think the numbers speak by themselves and I am talking about the IRC rating. For the ones that are not used to it, it is the opposed to PHRF, the bigger the number, the faster the boat.

First let's compare some of the best old performance boats with some modern performance cruisers. Let's start with older Swans, great performance boats on their day:

Swan 43 0.968
Swan 441 1.039 1.033
Swan 44 MKII 1.059 1.058
Swan 44 1.048
Swan 44 S&S 1.006
Swan 46 1.053
Swan 47 1.049 1.076
Swan 48 1.026 1.030
Swan 51 1.087
Swan 53 1.089 1.074
Swan 55 1.064

And let's compare them with the performance of modern Swans, not racing boats, but boats with a good cruising interior, as all Swans:

Swan 45 1.187 1.184
Swan 42 1.170
We see that even a 42fter is way faster than the old 50fters.
Other modern production performance cruisers with a good interior for a comparison with those old Swan:
XP 50 1.169
X50 1.149 1.130
X 46 1.114 1.123
Xp44 1.151 1.150
XP 38 1.081
X43 1.090
X40 1.077
First 50 1.158
First 45 1.117
First 40 1.087 1.078 1.082 1.075
Grand Soleil 56 1.164
Grand Soleil 54 1162
Grand Soleil 43 1.077
Grand Soleil 40 1.064
Dufour 44 1.096
Dufour 45e 1. 082
Elan 410 1.078
J133 1.119
J122 1.099 1.083 1.090
Salona 45 1.098 1.097
Salona 37 1.061
Arcona 410 1.071
Arcona 430 1.123
Comet 41s 1.098 1.086
Dehler 44 1.117
Finngulf 43 1.122
Gieffe GY51 1216
Dehler 34 1.008
First 33.7 1.010
Note that I am just talking about big production boats not about small series performance cruisers that are used almost only to race. The performance of those is far superior but they are very expensive (we could include the Swan 42 on this group):
Santa Cruz 37 1.140
Ker 39 1.120
King 40 1.117
Lets compare now the production performance cruisers with the performance of some British medium displacement high quality boats, famous ones, Oyster, Moody, Discovery and Bowman:
Oyster 62 1.126
Oyster 61 1.081 1.088
Oyster 56 1.056 1.078
Oyster 55 1.056
Oyster 54 1.078
Oyster 485 1.033
Oyster 49 1.017
Oyster 435 0.947
Moody 54 1.051 1.072
Moody 49 1.026
Moody 47 0.994 1.009 1.000
Moody 44 1.009 1.021 1.024 1.00
Bowman 42 1.004
Bowman 48 1.031
Bowman 46 1.010
Discovery 55 1.070
Hylas 47 0. 986
Trintella 45 1.029
Contest 48s 0.992
Island Packet 460 0.991
and finally let's compare the performance of these ones with the performance of main market mass production modern performance cruisers:
Hunter Legend 376 1.006 0.999
Hunter 37.5 1.008
Hunter Legend 466 1.014
Hunter 50 1.030
Bavaria 36 1.007
Bavaria 44 1.062 1.035
Bavaria 46 1.075 1.068 1.088
Bavaria 49 1.112
Bavaria 50 1.089 1.101
Jeanneau 49 1.051
Jeanneau 54 DS 1.129 1.106
Hanse 400e 1.049
Hanse 430e 1.080
Hanse 470 1.067
Hanse 531 1.105
Oceanis 473 1.051 1.071
Oceanis 50 1.075
Oceanis 523 1.140
I believe that with all this data each one can take their own conclusions. Remember IRC rating is very close to the real performance of the boats and if any type of boat had a favorable rating soon we would be seeing lots of sailors racing with that type of boat or model and winning all the races and that just doesn't happen. Normally the races, even in compensated, are won by some of the faster boats, almost all performance cruisers or pure racers.

Like equating stability with seaworthiness, equating IRC ratings with speed for a cruising boat is an arm-chair fallacy.

Speed in a cruising boat - which will not have multiple sail changes on board, and will not be fully crewed - is determined mostly by waterline length, D/L, underbody form, sail condition.

IRC ratings are heavily driven by SA/D. But SA/D is only key to speed in light wind. A boat with less SA/D will be faster once there's enough wind to be powered up. So without sail changes on board and crew to do them, a boat with high SA/D is at a disadvantage in winds beyond optimum strength for that sail plan.

IRC ratings also understate the advantage of size, since they assume racing condition without cruising gear on board.

Thus my boat has a similar rating to a Salona 45. In winds light enough for the Salona to use its much greater SA/D, and with both boats empty and stripped for racing, maybe they will have similar performance. But in cruising trim and in real life, my boat is one to two knots faster on every point of sail. In lighter wind, not so much. But when the wind pipes up to 20+, the Salona will be left far behind. This is not armchair speculation based on numbers, but real life experience with both boats.

Saying that this boat is faster than that one because it has more SA/D is a bit like saying this car is faster than that one because it has a higher gear. It might be true under some circumstances -- on a long downhill run, maybe. But in fact boats with high SA/D are just in a different "gear"; the optimum wind range is shifted downward, so that they have more power in light wind but have to be reefed earlier. So whether that makes the boat faster or not depends.

In the Med, I guess, or in Florida, a SA/D of 20 or more could be a good thing. Although I spent a few summers in the Aegean with the Meltemi blowing, and you wouldn't want that kind of sail plan there. Up here, it's way too much. If you're a cruiser with no changes of working sails, you'll be sailing around reefed all the time and being passed by boats with sail plans more suitable to the conditions.

My boat's SA/D is 16.5, which with a 120% yankee jib is about right for the summer here, but it's too much for other seasons. That's why I'm having a blade jib made over the winter -- for going upwind efficiently in 20 to 30 knots, an unfortunately common task in these latitudes.

[neilpride]

Originally Posted by Polux

You talk like a cruiser to whom sailing pleasure is indifferent but not all are like that. For some the pleasure of sailing is as important as sailing.

The difference you talk about speed is much more important. With the same size (40/42ft) a heavy boat average medium speeds of about 5.5K, performance ones about 7K. It looks not much but in 24 hours regarding the slower boat that means more 6.5 hours and a 15 days passage for the faster boat it will mean more 4 days. That's about the difference you see on the ARC regarding the average time passage between the two types of boats.

But more important than that are two other things: the pleasure of sailing a fast enjoyable boat, not to mention the pleasure of overtaking much bigger boats and, out of the trade winds, the incomparably more time one passes sailing than motoring.

To give you an idea last year I made about a 1000 NM cruising with 60L of diesel, most of it for charging the batteries, since i did not use the engine practically for nothing more. With a medium displacement boat I would be motoring 2/3 of the time and would have spent about 10 times more diesel.

But is not really a question of wasting money in diesel, it is about the pleasure of sailing instead of motoring. I like to sail as much as I like to cruise

Not really, you are based i think in the meditorranean , wher light air perfomance is a must if you dont want motor a lot, then light air boats are in their best enviroment, here tradewinds blow day by day, me and my wife we do the same as you, with a 17 tons heavy displacement boat, pulling up the anchor with the mainsail up and not a single drop of diesel used in a 15 days period, thx to solar panels and a nice wind generator, doing 6 and 7 knts up and down in the island chain.

You guys have a wrong misconception , linking heavy displacement with slow and poor sailing abilitys and slow passages, wrong and wrong, there is slow pigs and there is brilliant faster pigs, after all i probe that to myself in a Las Palmas Antigua in 16 days in a 62 ft Steel cutter with a weight close to 32 tons doing even 10 knts in the surfs , a clasic big and heavy boat with a modern rig, tall , powerfull, and with a well designed sailplan by north sails..

In my last delivery , a Lagoon 380 from Sables D Olone to Martinique, from Las palmas to Martinique take me 22 days, doing a lot of light air sailing and strong trades in between, so the funy advice from the lagoon agent in Olones claiming that im going to fly with the 38 probe wrong, fly my arse,, its a slow boat until you are surfing down waves with sail up, it all depend of the sailplan and the rig, i have a tall rig versión in my boat, doublé spreader, the original rig is a short single spreader stick more pointed to beam reach sailing than other point of sailing, the change from a semi batten mainsail to a full battem sail make a huge diference ,,

I can say that in many occasions we left behind more moder light cruising boats , by no chance our bow plunge in the waves and keep going where the light boats pound and loose speed, anyway for us the goal is to sail from A to B in safety and with a decent overall sog.

I keep in mind that to sail that new light cruising boats fast they need to be pushed hard, sailing really fast is stressful, unles you have a bloody racing crew, you loose confort and the gear is tested hard , crossing the pond in race mode in a light cruising boat is looking for troubles unless you have a tank like the moody, sooner or later you need to stop and think ,,,wtf is a 3000 miles passage, dont make sense broke something here, thats what we think me and my wife surfing with the 380 sometimes at 16 knts, believe me , 16 knts surfing a wave in a couple of ocassions, the boat suffer , the rig suffer , and you risk to broke something...

Saying generalized that heavy displacement boats are slow is plain wrong.

[Dockhead]

Originally Posted by neilpride

Not really, you are based i think in the meditorranean , wher light air perfomance is a must if you dont want motor a lot, then light air boats are in their best enviroment, here tradewinds blow day by day, me and my wife we do the same as you, with a 17 tons heavy displacement boat, pulling up the anchor with the mainsail up and not a single drop of diesel used in a 15 days period, thx to solar panels and a nice wind generator, doing 6 and 7 knts up and down in the island chain.

You guys have a wrong misconception , linking heavy displacement with slow and poor sailing abilitys and slow passages, wrong and wrong, there is slow pigs and there is brilliant faster pigs, after all i probe that to myself in a Las Palmas Antigua in 16 days in a 62 ft Steel cutter with a weight close to 32 tons doing even 10 knts in the surfs , a clasic big and heavy boat with a modern rig, tall , powerfull, and with a well designed sailplan by north sails..

In my last delivery , a Lagoon 380 from Sables D Olone to Martinique, from Las palmas to Martinique take me 22 days, doing a lot of light air sailing and strong trades in between, so the funy advice from the lagoon agent in Olones claiming that im going to fly with the 38 probe wrong, fly my arse,, its a slow boat until you are surfing down waves with sail up, it all depend of the sailplan and the rig, i have a tall rig versión in my boat, doublé spreader, the original rig is a short single spreader stick more pointed to beam reach sailing than other point of sailing, the change from a semi batten mainsail to a full battem sail make a huge diference ,,

I can say that in many occasions we left behind more moder light cruising boats , by no chance our bow plunge in the waves and keep going where the light boats pound and loose speed, anyway for us the goal is to sail from A to B in safety and with a decent overall sog.

I keep in mind that to sail that new light cruising boats fast they need to be pushed hard, sailing really fast is stressful, unles you have a bloody racing crew, you loose confort and the gear is tested hard , crossing the pond in race mode in a light cruising boat is looking for troubles unless you have a tank like the moody, sooner or later you need to stop and think ,,,wtf is a 3000 miles passage, dont make sense broke something here, thats what we think me and my wife surfing with the 380 sometimes at 16 knts, believe me , 16 knts surfing a wave in a couple of ocassions, the boat suffer , the rig suffer , and you risk to broke something...

Saying generalized that heavy displacement boats are slow is plain wrong.

All other things being equal, a heavier boat of course is slower. That's because a heavier boat needs that much more buoyancy which means more wetted surface which means more drag.

So anything you can do to lighten any boat will always make it faster.

However, everything else you say is very true -- mass improves seaworthiness and comfort, all other things being equal.

Besides that, a heavier boat is less sensitive to loads. So the theoretical advantage of a light boat when comparing light ship displacements is reduced as normal cruising loads are added. This is particularly important to boats which are cruised long term, or lived aboard.

So very light, small, high performance boats do have big disadvantages as cruisers.

Size can make up for a low D/L ratio. So the bigger the boat, the better it can tolerate a low D/L without becoming uncomfortable and/or insufficiently seaworthy.

[neilpride]

Yes off course, more drag and wetted surface, by nature cant compete in light winds with a similar in waterline lenght light boat , all the HP come from the rig and sails, so a sturdy sailplan and rig able to carry more sail in a wide range of conditions win , Dorade a old S&S design beat in the last TRANSPAC more modern sailplans, boats..

Medium and heavy boats with fine entrys in the bow but not so radical like many flat bow modern designs also have a advantage , they dont loose track and speed in moderate conditions, i mean i know that because i own a C&c, sailing up to weather in anything beyond 2 meters waves is a pain in the ass, the boat slam the waves and pound horrible, so slow down is the only option , with my actual boat doing 6 knts in 3 meters waves is not a problem
at all, is not very confy but you dont feel the boat slaming or pounding, its just plounge in the waves and keep going..... So to me this is very funy , you know the IRC ratings and so on, when the reality is really diferent, a cruiser racer its a cruiser racer not a cruiser , i always say, a boat with litle tankage in fuel and wáter is made for inshore sailing or coastal.... and i know this by a personal fact, running low on batteries with 35 knts along the Portugese coast and trying to fill the main tanks with a Jerry can on deck cliped to the cokpit is crap....

[Polux]

Originally Posted by Dockhead

All other things being equal, a heavier boat of course is slower. That's because a heavier boat needs that much more buoyancy which means more wetted surface which means more drag.

So anything you can do to lighten any boat will always make it faster.

However, everything else you say is very true -- mass improves seaworthiness and comfort, all other things being equal.

Besides that, a heavier boat is less sensitive to loads. So the theoretical advantage of a light boat when comparing light ship displacements is reduced as normal cruising loads are added. This is particularly important to boats which are cruised long term, or lived aboard.

So very light, small, high performance boats do have big disadvantages as cruisers.

Size can make up for a low D/L ratio. So the bigger the boat, the better it can tolerate a low D/L without becoming uncomfortable and/or insufficiently seaworthy.

Nice I agree with all and even with what regards seaworthiness, if we are talking about the same type of boat. There are disadvantages and advantages between a fast performance cruiser and a medium weight cruiser and that's why both are used to do extensive cruising. Each cruiser will chose between the advantages and disadvantages, the best pack for his lifestyle and the way he enjoy cruising and living. Not all carry big amounts of stuff while cruising (I know some that carry a lot less than me) and the amenities and comforts one needs or enjoy are different from sailor to sailor as well as the importance of fun while sailing has in what regards cruising.

[smackdaddy]

Originally Posted by robert sailor

Mmm! My bad, seems the rating page was an old one that I have obviously used for a little to long, sorry about that.

I bet that hurt.

[smackdaddy]

Originally Posted by neilpride

Nothing personal, but all this IRC numbers or whatever ,,make me dizzy,

I'll boil it down for you...all the older Swans are slower than the Beneteau Oceanis 52. BUT they are a tiny bit faster than the Hunter 50 - so you got that going for you.

[Polux]

Originally Posted by neilpride

..
Medium and heavy boats with fine entrys in the bow but not so radical like many flat bow modern designs also have a advantage , they dont loose track and speed in moderate conditions, i mean i know that because i own a C&c, sailing up to weather in anything beyond 2 meters waves is a pain in the ass, the boat slam the waves and pound horrible, so slow down is the only option , with my actual boat doing 6 knts in 3 meters waves is not a problem
at all, is not very confy but you dont feel the boat slaming or pounding, its just plounge in the waves and keep going..... ...

I don't know the C&C you are talking about but if it is that bad on those conditions you should get ride of it. I had already told (I don't know if it was on this thread) that I can go a lot better upwind with short steep 2 m waves and winds between 20 and 30K, than any similar sized (or even slightly bigger) medium weight boat, or it is at least the experience I had with several of those boats, including a good one on those conditions, a Moody 425. Your heavy boat is a lot better than the Moody? Regarding the Moody I don't really know if it was a 425, maybe Robert can help? It was a 42/44 Moody, a British one, a nice looking boat.

Regarding slamming and difficulty to knife through the wave upwind or make speed maybe you should look at the fine entries of a modern performance cruiser and then you will understand why they perform very well upwind. The finer entries and a lot more power than on a medium cruiser will do the job.

[neilpride]

Originally Posted by smackdaddy

I'll boil it down for you...all the older Swans are slower than the Beneteau Oceanis 52. BUT they are a tiny bit faster than the Hunter 50 - so you got that going for you.

Lie, wrong, i bet you the swan is faster in moderate conditions heavy conditions.

[neilpride]

Originally Posted by Polux

I don't know the C&C you are talking about but if it is that bad on those conditions you should get ride of it. I had already told (I don't know if it was on this thread) that I can go a lot better upwind with short steep 2 m waves and winds between 20 and 30K, than any similar sized (or even slightly bigger) medium weight boat, or it is at least the experience I had with several of those boats, including a good one on those conditions, a Moody 425. Your heavy boat is a lot better than the Moody? Regarding the Moody I don't really know if it was a 425, maybe Robert can help? It was a 42/44 Moody, a British one, a nice looking boat.

Regarding slamming and difficulty to knife through the wave upwind or make speed maybe you should look at the fine entries of a modern performance cruiser and then you will understand why they perform very well upwind. The finer entries and a lot more power than on a medium cruiser will do the job.

The only thing clear in this post is the flat bow section área , a welcome for pounding and slaming.